package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.User;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //查询优惠卷
        SeckillVoucher voucher=seckillVoucherService.getById(voucherId);
        //判断秒杀是否开始
        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
            //尚未开始
            return Result.fail("秒杀尚未开始");
        }
        //判断秒杀是否已经结束
        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
            //已经结束
            return Result.fail("秒杀已经结束");
        }
        //判断库存是否充足
        if(voucher.getStock()<1){
            //库存不足
            return Result.fail("库存不足！");
        }
        Long userId=UserHolder.getUser().getId();
        //创建锁对象
        SimpleRedisLock lock=new SimpleRedisLock("order:"+userId,stringRedisTemplate);
        //获取锁
        boolean isLock=lock.tryLock(1200);
        //判断是否获取锁成功
        if(!isLock){
            //获取锁失败，返回错误或重试
            return Result.fail("不能重复下单");
        }
        try {
            //获取代理对象,事务才会生效
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }finally {
            //释放锁
            lock.unlock();
        }

    }

    @Transactional
    public Result createVoucherOrder(Long voucherId){
        //一人一单
        //用户Id
        Long userId=UserHolder.getUser().getId();
            //查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            //判断是否存在
            if (count > 0) {
                //用户已经购买过
                return Result.fail("用户已经购买过一次！");
            }
            //以上判断完后说明有库存
            //扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock=stock-1")
                    .eq("voucher_id", voucherId).gt("stock", 0)//乐观锁
                    .update();
            if (!success) {
                //扣减失败
                return Result.fail("库存不足！");
            }
            //创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            //订单id
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            voucherOrder.setUserId(userId);
            //代金卷Id
            voucherOrder.setVoucherId(voucherId);
            //存入数据库
            save(voucherOrder);
            //返回订单id
            return Result.ok(orderId);
    }
}
